<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->

      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面 TODO -->
      <!-- 课程封面-->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss'"
          class="avatar-uploader">
          <img :src="courseInfo.cover" style="height: 300px;width: 500px">
        </el-upload>
      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>


    </el-form>
  </div>
</template>

<script>
import course from "@/api/edu/course";
import subject from "@/api/edu/subject";
import Tinymce from '@/components/Tinymce'
export default {
  components: { Tinymce },
  data(){
    return{
      saveBtnDisabled:false,
      courseInfo:{
        title: '',
        subjectId: '', //二级分类
        subjectParentId:'', //一级分类
        teacherId: '',
        lessonNum: 0,
        description: '',
        cover: '/static/天使1.jpg',
        price: 0
      },
      courseId:'',
      BASE_API: process.env.BASE_API, // 接口API地址
      teacherList:[],
      subjectOneList:[],
      subjectTwoList:[]
    }
  },
  created(){
    //获取路由id值
    if (this.$route.params && this.$route.params.id){
      this.courseId = this.$route.params.id
      this.getInfo()
    }else {
      //初始化所有讲师
      this.getListTeacher()

      //初始化一级分类
      this.getOneSubject()
    }

  },
  watch: { //监听
    $route(to, from) {
      this.init()
    }
  },
  methods:{
    //根据课程id查询
    getInfo(){
      course.getCourseInfoId(this.courseId)
      .then(response=>{
        //在courseinfo课程信息中，包含一级分类和二级分类id
        this.courseInfo = response.data.courseInfoVo
        //1 查询所有的分类，包括一级和二级
        subject.getSubjectList()
        .then(response=>{
          //2 获取所有的一级分类
          this.subjectOneList = response.data.list
          //3 遍历所有一级分类，比较courseinfo里的一级分类和所有一级分类id
          for (var i = 0;this.subjectOneList.length;i++){
            var oneSubject = this.subjectOneList[i]
            if (this.courseInfo.subjectParentId == oneSubject.id){
              this.subjectTwoList = oneSubject.children
            }
          }
        })
        //初始化所有讲师
        this.getListTeacher();
      })
    },
    init(){
      if (this.$route.params && this.$route.params.id) {
        this.getInfo()
      }else {
        this.courseInfo={cover: '/static/天使1.jpg',}

      }
    },
    handleAvatarSuccess(res,file){ //上传成功
      this.courseInfo.cover = res.data.url;
    },
    beforeAvatarUpload(file){ //上传之前
      const isJPG = file.type === 'image/jpeg'
      const isLt2M = file.size / 1024 / 1024 < 2
      if (!isJPG) {
        this.$message.error('上传头像图片只能是 JPG 格式!')
      }
      if (!isLt2M) {
        this.$message.error('上传头像图片大小不能超过 2MB!')
      }
      return isJPG && isLt2M
    },
    //点击某个一级分类，触发change，显示对应二级分类
    subjectLevelOneChanged(value){ //value就是一级分类的id值
      // alert(value)
      for (var i=0; i < this.subjectOneList.length;i++){
        var oneSubject = this.subjectOneList[i]
        //判断 ：所有一级分类id和点击一级分类的id是否一样
        if(oneSubject.id === value){
          this.subjectTwoList = oneSubject.children
          this.courseInfo.subjectId = ''
        }
      }
    },

    //查询所有的一级分类
    getOneSubject(){
      subject.getSubjectList()
      .then(response=>{
        this.subjectOneList = response.data.list
      })
    },
    getListTeacher(){
      course.getListTeacher()
      .then(response=>{
        this.teacherList = response.data.items
      })
    },
    //添加课程
    addCourse(){
      course.addCourseInfo(this.courseInfo)
        .then(response=>{
          //提示信息
          this.$message({
            type: 'success',
            message: '添加课程信息成功'
          })

          //跳转到下一步
          this.$router.push({path:'/course/chapter/'+response.data.courseId})
        })
    },
    //修改课程
    updateCourse(){
      course.updateCourseInfo(this.courseInfo)
      .then(response=>{
        //提示信息
        this.$message({
          type: 'success',
          message: '修改课程信息成功'
        })

        //跳转到下一步
        this.$router.push({path:'/course/chapter/'+this.courseId})
      })
    },
    saveOrUpdate(){
      if(!this.courseInfo.id){
        this.addCourse()
      }else {
        this.updateCourse()
      }
    },

  }
}
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>
